This invention relates to a slide hatch for a bulk carrier, in particular for a vehicle carrier for dry cement. The slide hatch can be used on any bulk carrier vehicle of the type used for transport of dry powdered or granular material that is free flowing in a hopper style container. This description utilizes a cement carrier as a preferred example of the transport carrier contemplated. Bulk transport of dry cement is accomplished utilizing a gondola-style trailer that is loaded with cement from a top port by means of a hose or chute. Typically, the gondola has a tank with sloping sides that converge to a bottom discharge for gravity feed of the cement to a discharge hose that is used to pneumatically deliver the bulk cement to a destination for storage or mixing. To assist in the discharge of the fine powder cement, the gondola tank is pressurized to both compensate for volumetric displacement by the discharging cement and to assist in moving the cement to the discharge pump.
To maintain a pressure within the gondola tank, the hatch cover must have a sealed engagement with the hatch port at the top of the tank. Typically, the hatch cover is connected to the tank with a hinge and a series of threaded dogs mounted around the hatch cover. When the tank is refilled, the hatch cover must be opened which has customarily required that the driver or assistant climb to the top of the trailer and manually disengage the tie-down dogs to open the hatch. Not only is this task time consuming, but because of the configuration of the tank and carrier trailer the task is dangerous as well.
The slide hatch for bulk carriers of this invention is designed to enable removal of a hatch cover by an automatic or manual actuator. The system for displacing the hatch cover is designed to not only position the hatch cover over the access port but to forcibly seat the hatch cover on the port rim to create a hermetic seal for allowing internal pressurization of the gondola tank. In this manner removal and replacement of the hatch cover can be accomplished automatically with a piston type actuator operated from inside the vehicle cab, or manually from the end of the trailer without having to climb on top of the tank.